Chaperones and protein folding in the archaea

2009 ◽  
Vol 37 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Andrew T. Large ◽  
Martin D. Goldberg ◽  
Peter A. Lund
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Heat Shock Protein ◽  
Haloferax Volcanii ◽  
Functional Specialization ◽  
Type I ◽  
Type Ii ◽  
Shock Proteins

A survey of archaeal genomes for the presence of homologues of bacterial and eukaryotic chaperones reveals several interesting features. All archaea contain chaperonins, also known as Hsp60s (where Hsp is heat-shock protein). These are more similar to the type II chaperonins found in the eukaryotic cytosol than to the type I chaperonins found in bacteria, mitochondria and chloroplasts, although some archaea also contain type I chaperonin homologues, presumably acquired by horizontal gene transfer. Most archaea contain several genes for these proteins. Our studies on the type II chaperonins of the genetically tractable archaeon Haloferax volcanii have shown that only one of the three genes has to be present for the organisms to grow, but that there is some evidence for functional specialization between the different chaperonin proteins. All archaea also possess genes for prefoldin proteins and for small heat-shock proteins, but they generally lack genes for Hsp90 and Hsp100 homologues. Genes for Hsp70 (DnaK) and Hsp40 (DnaJ) homologues are only found in a subset of archaea. Thus chaperone-assisted protein folding in archaea is likely to display some unique features when compared with that in eukaryotes and bacteria, and there may be important differences in the process between euryarchaea and crenarchaea.

scholarly journals The genome of a subterrestrial nematode reveals an evolutionary strategy for adaptation to heat

2019 ◽  
Author(s):  
Deborah J. Weinstein ◽  
Sarah E. Allen ◽  
Maggie C. Y. Lau ◽  
Mariana Erasmus ◽  
Kathryn C. Asalone ◽  
...  
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
Heat Shock ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Heat Shock Proteins ◽  
Evolutionary Strategy ◽  
Adaptation To Heat ◽  
Heterotrophic Prokaryotes ◽  
Shock Proteins

AbstractThe nematode Halicephalobus mephisto was originally discovered inhabiting a deep terrestrial aquifer 1.3 km underground. H. mephisto can thrive under conditions of abiotic stress including heat and minimal oxygen, where it feeds on a community of both chemolithotrophic and heterotrophic prokaryotes in an unusual ecosystem isolated from the surface biosphere. Here we report the comprehensive genome and transcriptome of this organism, identifying a signature of adaptation: an expanded repertoire of 70 kilodalton heat-shock proteins (Hsp70) and avrRpt2 induced gene 1 (AIG1) proteins. We find that positive selection has driven the expansion of Hsp70 genes, which are also transcriptionally induced upon growth under heat stress. We further show that AIG1 may have been acquired by horizontal gene transfer (HGT) from a rhizobial fungus. Over one-third of the genes of H. mephisto are novel, highlighting the divergence of this nematode from other sequenced organisms. This work sheds light on the genomic strategies of adaptation to heat in the first complete subterrestrial eukaryotic genome.

scholarly journals The genome of a subterrestrial nematode reveals adaptations to heat

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Deborah J. Weinstein ◽  
Sarah E. Allen ◽  
Maggie C. Y. Lau ◽  
Mariana Erasmus ◽  
Kathryn C. Asalone ◽  
...  
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
Heat Shock ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Heat Shock Proteins ◽  
Heat Tolerance ◽  
Heterotrophic Prokaryotes ◽  
Shock Proteins ◽  
Genomic Basis

AbstractThe nematode Halicephalobus mephisto was originally discovered inhabiting a deep terrestrial aquifer 1.3 km underground. H. mephisto can thrive under conditions of abiotic stress including heat and minimal oxygen, where it feeds on a community of both chemolithotrophic and heterotrophic prokaryotes in an unusual ecosystem isolated from the surface biosphere. Here we report the comprehensive genome and transcriptome of this organism, identifying a signature of adaptation: an expanded repertoire of 70 kilodalton heat-shock proteins (Hsp70) and avrRpt2 induced gene 1 (AIG1) proteins. The expanded Hsp70 genes are transcriptionally induced upon growth under heat stress, and we find that positive selection is detectable in several members of this family. We further show that AIG1 may have been acquired by horizontal gene transfer (HGT) from a rhizobial fungus. Over one-third of the genes of H. mephisto are novel, highlighting the divergence of this nematode from other sequenced organisms. This work sheds light on the genomic basis of heat tolerance in a complete subterrestrial eukaryotic genome.

Chaperone families and interactions in metazoa

2016 ◽  
Vol 60 (2) ◽  
pp. 237-253 ◽  
Author(s):  
Yael Bar-Lavan ◽  
Netta Shemesh ◽  
Anat Ben-Zvi
Keyword(s):  
Gene Expression ◽  
Quality Control ◽  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Molecular Chaperones ◽  
Diverse Group ◽  
Acute Effects ◽  
Shock Proteins

Quality control is an essential aspect of cellular function, with protein folding quality control being carried out by molecular chaperones, a diverse group of highly conserved proteins that specifically identify misfolded conformations. Molecular chaperones are thus required to support proteins affected by expressed polymorphisms, mutations, intrinsic errors in gene expression, chronic insult or the acute effects of the environment, all of which contribute to a flux of metastable proteins. In this article, we review the four main chaperone families in metazoans, namely Hsp60 (where Hsp is heat-shock protein), Hsp70, Hsp90 and sHsps (small heat-shock proteins), as well as their co-chaperones. Specifically, we consider the structural and functional characteristics of each family and discuss current models that attempt to explain how chaperones recognize and act together to protect or recover aberrant proteins.

scholarly journals Toxin Inactivation in Toxin/Antitoxin Systems

2019 ◽  
Author(s):  
Laura Fernandez-Garcia ◽  
Jun-Seob Kim ◽  
Maria Tomas ◽  
Thomas K. Wood
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Metabolic Activity ◽  
Type I ◽  
Type Ii ◽  
Genetic Elements ◽  
Type V ◽  
Chromosomal Mutations

Toxin/antitoxin (TA) systems are used primarily to inhibit phage, reduce metabolic activity during stress, and maintain genetic elements. Given the extreme toxicity of some of the toxins of these TA systems, we were curious how the cell silences toxins, if the antitoxin is inactivated or when toxins are obtained without antitoxins via horizontal gene transfer. Here we find that the RalR (type I), MqsR (type II), GhoT (type V), and Hha (type VII) toxins are inactivated primarily by a mutation that inactivates the toxin promoter or via the chromosomal mutations iraM and mhpR.

scholarly journals PL - 039 Heat Shock Proteins in human single skeletal muscle fibres resist age associated alterations and differentially respond to high-intensity exercise training

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Robyn Murphy ◽  
Aaron C Petersen ◽  
Itamar Levinger ◽  
Michael J McKenna ◽  
Victoria L Wyckelsma
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Young Adults ◽  
Heat Shock ◽  
Fibre Type ◽  
Type I ◽  
Type Ii ◽  
Older Individuals ◽  
Shock Proteins ◽  
And Function

Objective Heat shock proteins (HSPs) are ubiquitously expressed proteins that help preserve cellular homeostasis. Within mammalian skeletal muscle three of the better characterised HSPs are HSP72, HSP27 and αB-crystallin. Among other roles, these three HSPs are involved in regulation of muscle mass and function and may be of importance in ageing. HSP’s are fibre-type dependent in rat skeletal muscle and thus examining these proteins in humans should be completed on the single fibre level, particularly in ageing where maladaptations primarily occur in Type II fibres. High-Intensity Training (HIT) is a commonly used method to improve muscle health and function in the elderly, but HSP adaptability to training has not yet been investigated.   Methods This study examined isolated single muscle fibre segments collected from freeze-dried vastus lateralis muscle samples from young (25 /- 3 year old) and older (70 /- 4 year old) healthy individuals.  A further sample was collected from the older individuals following 12 weeks of HIT, where they performed 4 x 4 min @ ~90-95% of peak heart rate (HR), with 4 min active recovery at 50-60% peak HR Results Basal expression of HSP’s in skeletal muscle: HSP70 tended to be higher in Type I fibres compared to Type II in young adults (p=0.08) and was higher in Type I compared to Type II fibres of older adults (p=0.03). HSP27 abundance was higher in Type I fibres compared to Type II in young adults (p=0.01) and tended to be higher in Type I compared to Type II fibres in older adults (p=0.07). The abundance of αβ-crystallin was more abundant in Type I fibres compared to Type II in both young and older adults (p<0.05).  Preliminary data revealed that the abundance of pABCser59 and pHSP2782 displayed no fibre-type specific abundances in either young or older adults. Age effects on HSP’s: There was no difference in the abundance of HSP70, HSP27, ABC or pHSP2782 between young and older adults in either Type I or Type II fibres. There was an increase in the abundance of pABCser59 in Type I fibres in older adults compared to Type I fibres of young adults (p=0.03), with no difference in Type II fibres. Effects of HIT on HSP’s:  HIT in the older individuals increased the abundance of HSP70 in Type I fibres (p<0.01) but not Type II. HIT tended to decrease the abundance of HSP27 in Type I fibres (0.92±0.66, p=0.06) and tended to increase the abundance of αβ-crystallin in Type I fibres (1.03±1.51 p=0.07). Conclusions These results revealed that in healthy, older individuals, the basal levels of HSP27, ABC or pHSP2782 are not different to those in young adults in either Type I or Type II fibres. This could indicate that the muscle from the older individuals was not compromised.  Interestingly, in response to HIT there were varying changes between these HSP’s, and of note these occurred only in Type I fibres.  Given that during HIT Type II fibres would be activated to a greater extent, it appears that the recovery phases of the HIT were most responsive to HSPs.

scholarly journals A new antisarcoma strategy: multisubtype heat shock protein/peptide immunotherapy combined with PD-L1 immunological checkpoint inhibitors

2021 ◽  
Author(s):  
H. Li ◽  
X. Sui ◽  
Z. Wang ◽  
H. Fu ◽  
Z. Wang ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Lung Metastasis ◽  
Checkpoint Inhibitors ◽  
Combined Therapy ◽  
Peptide Vaccine ◽  
Tumor Environment ◽  
Immune Check Point Inhibitor ◽  
Shock Proteins ◽  
Sarcoma Treatment

AbstractOsteosarcoma, a common malignant tumor in orthopedics, often has a very poor prognosis after lung metastasis. Immunotherapy has not achieved much progress in the treatment because of the characteristics of solid tumors and immune environment of osteosarcoma. The tumor environment is rather essential for sarcoma treatment. Our previous study demonstrated that heat shock proteins could be used as antitumor vaccines by carrying tumor antigen peptides, and we hypothesize that an anti-osteosarcoma effect may be increased with an immune check point inhibitor (PD-L1 inhibitor) as a combination treatment strategy. The present study prepared a multisubtype mixed heat shock protein osteosarcoma vaccine (mHSP/peptide vaccine) and concluded that the mHSP/peptide vaccine was more effective than a single subtype heat shock protein, like Grp94. Therefore, we used the mHSP/peptide vaccine in combination with a PD-L1 inhibitor to treat osteosarcoma, and the deterioration of osteosarcoma was effectively hampered. The mechanism of combined therapy was investigated, and AKT expression participates with sarcoma lung metastasis. This study proposed an antisarcoma strategy via stimulation of the immune system as a further alternative approach for sarcoma treatment and elucidated the mechanism of combined therapy.

Principles of chaperone-mediated protein folding

1995 ◽  
Vol 348 (1323) ◽  
pp. 107-112 ◽  
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Cellular Protein ◽  
Chaperone Proteins ◽  
Shock Proteins ◽  
Polypeptide Chains

The recent discovery of molecular chaperones and their functions has changed dramatically our view of the processes underlying the folding of proteins in vivo . Rather than folding spontaneously, most newly synthesized polypeptide chains seem to acquire their native conformations in a reaction mediated by chaperone proteins. Different classes of molecular chaperones, such as the members of the Hsp70 and Hsp60 families of heat-shock proteins, cooperate in a coordinated pathway of cellular protein folding.

scholarly journals Cross-priming of minor histocompatibility antigen-specific cytotoxic T cells upon immunization with the heat shock protein gp96.

1995 ◽  
Vol 182 (3) ◽  
pp. 885-889 ◽  
Author(s):  
D Arnold ◽  
S Faath ◽  
H Rammensee ◽  
H Schild
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Tumor Cells ◽  
Mhc Class I ◽  
Donor Cell ◽  
Class I ◽  
Heat Shock Protein Gp96 ◽  
Shock Proteins

Vaccination of mice with heat shock proteins isolated from tumor cells induces immunity to subsequent challenge with those tumor cells the heat shock protein was isolated from but not with other tumor cells (Udono, H., and P.K. Srivastava. 1994. J. Immunol. 152:5398-5403). The specificity of this immune response is caused by tumor-derived peptides bound to the heat shock proteins (Udono., H., and P.K. Srivastava. 1993. J. Exp. Med. 178:1391-1396). Our experiments show that a single immunization with the heat shock protein gp96 isolated from beta-galactosidase (beta-gal) expressing P815 cells (of DBA/2 origin) induces cytotoxic T lymphocytes (CTLs) specific for beta-gal, in addition to minor H antigens expressed by these cells. CTLs can be induced in mice that are major histocompatibility complex (MHC) identical to the gp96 donor cells (H-2d) as well as in mice with a different MHC (H-2b). Thus gp96 is able to induce "cross priming" (Matzinger, P., and M.J. Bevan. 1977. Cell. Immunol. 33:92-100), indicating that gp96-associated peptides are not limited to the MHC class I ligands of the gp96 donor cell. Our data confirm the notion that samples of all cellular antigens presentable by MHC class I molecules are represented by peptides associated with gp96 molecules of that cell, even if the fitting MHC molecule is not expressed. In addition, we extend previous reports on the in vivo immunogenicity of peptides associated gp96 molecules to two new groups of antigens, minor H antigens, and proteins expressed in the cytosol.

scholarly journals hsp26 of Saccharomyces cerevisiae is related to the superfamily of small heat shock proteins but is without a demonstrable function.

1989 ◽  
Vol 9 (11) ◽  
pp. 5265-5271 ◽  
Author(s):  
R E Susek ◽  
S L Lindquist
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mutational Analysis ◽  
Small Heat Shock Protein ◽  
Major Effect ◽  
Selfish Dna ◽  
Dna Elements ◽  
Cloned Gene ◽  
Shock Proteins

Analysis of the cloned gene confirms that hsp26 of Saccharomyces cerevisiae is a member of the small heat shock protein superfamily. Previous mutational analysis failed to demonstrate any function for the protein. Further experiments presented here demonstrate that hsp26 has no obvious regulatory role and no major effect on thermotolerance. It is possible that the small heat shock protein genes originated as primitive viral or selfish DNA elements.

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